Sunderland's leading scorer Darren Bent is struggling with a hamstring injury which could see him sidelined for up to three weeks. The England striker fired the winner against Arsenal at the weekend, but he finished the game clutching his hamstring.
Black Cats boss Steve Bruce is now waiting to hear the results of scans.
"Darren's had a scan and we're waiting for the results," said Bruce.
"If it is his hamstring, we could be looking at about three weeks out.
"We won't know anything more until the results come back so we will have to keep our fingers crossed."